Dynamic create a TppField and TppDBText but show nothing

rbuser

Hi,

I try to create a TppField and TppDBText in RAP and hope the result will
shown on report, but it doesn' show out:

procedure GlobalOnCreate;
var TppDBText;
F: TppField;
begin
ShowMessage('Do it');
F := TppField.Create(Main);
F.FieldName := 'Company';
F.DataType := dtString;
F.FieldLength := 100;
F.DataPipeline := Main;
Main.AddField(F);

D := TppDBText.Create(Report);
D.DataPipeline := Main;
D.DataField := 'Company';
D.Band := Detail;
D.Left := 3.0;
D.Width := 1.5;
D.Color := clYellow;
end;

The 'Main' is the TppDBPipeline and the AddField method was defined via
RTTI.

Thank you very much.

Best Regards,
C. Yang

nardmoseley

Try the same code from Delphi first, its easier to trace in the debugger
that way. And as a first step, execute the code prior to calling
report.Print

1. RB 9 introduces some new events to allow preparing data from RAP. The
Report.OnInitializeParameters and BeforeOpenDataPipelines events.

I think the GlobalOnCreate event occurs too late.

2. In your example is there a TDataSet field that corresponds to the
F.FieldName? Try tracing the source code for TppDBPipeline.GetFieldValue

3. Remove the Main.AddField() line. Setting the Field.DataPipeline is
sufficient.



--
Nard Moseley
Digital Metaphors Corporation
www.digital-metaphors.com